Filter unit



FIG. 1 is a first perspective view of a filter unit showing my newdesign;

FIG. 2 is a second perspective view thereof;

FIG. 3 is a third perspective view thereof;

FIG. 4 is a fourth perspective view thereof;

FIG. 5 is a front elevational view thereof;

FIG. 6 is a rear elevational view thereof;

FIG. 7 is a left side view thereof;

FIG. 8 is a right side view thereof;

FIG. 9 is a top plan view thereof;

FIG. 10 is a bottom plan view therof;

FIG. 11 is an enlarged view of portion 11 of FIG. 3;

FIG. 12 is an enlarged view of portion 12 of FIG. 4; and,

FIG. 13 is an enlarged view of portion 13 of FIG. 8.

CLAIM The ornamental design for a filter unit, as shown and described.